The battle over the initiative, launched by Texas oil giants Valero and Tesoro, will pit that industry against environmentalists and the state's clean-tech businesses.

California headed for a high-stakes battle over global warming Tuesday, as an oil industry-backed measure to suspend the state's aggressive climate-change law qualified for the November ballot.

The fight will pit the state's powerful environmental organizations and clean-tech businesses against the oil and manufacturing industries. It also arrays many conservative political leaders, including the GOP nominee for governor, Meg Whitman, against Gov. Arnold Schwarzenegger, a fellow Republican who regards the global warming law as a key part of his legacy.

Whitman has said she would suspend the global-warming law for one year but has not endorsed the initiative.

The measure, launched six months ago by Texas oil giants Valero Energy Inc. and Tesoro Corp., comes as the industry has fallen under intense scrutiny in the wake of the Gulf of Mexico oil spill disaster.

Under California's law, known as AB 32, the state is setting limits on greenhouse gas emissions from automobiles, oil refineries and other industries, and will probably require that a third of the state's electricity come from renewable sources by 2020, up from about 15% today. New rules under the law would encourage sales of more fuel-efficient cars.

Supporters of the law say it has spurred a large market for solar, wind and other clean energy sources.

But backers of the ballot effort, who are calling their measure "the California Jobs Initiative paint the climate law as "an energy tax." Their initiative would halt enforcement of the law until unemployment in the state, now over 12%, sinks to 5.5% for at least a year.

"AB 32 will impose billions of dollars in higher utility rates and fuel prices on California families when they can least afford it," said Jon Coupal, president of the Howard Jarvis Taxpayers Assn, and co-chair of the initiative campaign.

Proponents of the measure spent $3 million, more than two thirds of it contributed by the two Texas companies and other energy interests, to gather more than 800,000 signatures to place the measure on the ballot. To qualify, the initiative needed 433,971 signatures, equal to 5% of the ballots cast in the 2006 general election.

"The Texas oil companies think if they can kill their clean energy competition in California, they can do it everywhere," said Steve Maviglio, a spokesman for the initiative's opponents, who set up a campaign committee called Californians for Clean Energy and Jobs.

Valero, which owns two California refineries, has mounted an aggressive campaign against federal efforts to pass climate legislation, including a House bill that was modeled in part on California's law. Environmentalists acknowledge that postponing California's rules to limit greenhouse gases could damage the chances of any federal legislation.

Supporters of the law have marshaled a who's who of the clean-tech world, including 300 companies, to raise money to fight the initiative. "AB 32 is an incubator of innovation," said Google Chief Executive Eric Schmidt. The law, he said, would lead to "new job creation in many sectors as business responds to the need for energy-efficient buildings, transportation and a growing portfolio of renewable energy resources."

Although the gulf oil disaster could turn undecided voters against the measure, proponents already face a steep hurdle in the wording that will describe the ballot. The title was set by the office of state Atty. Gen. Jerry Brown, a supporter of AB 32 and the Democratic gubernatorial candidate. It will be described on the ballot as follows: "Suspends air pollution control laws requiring major polluters to report and reduce greenhouse gas emissions that cause global warming until unemployment drops below specified level for full year."

The ballot wording goes on to say the measure "requires the state to abandon implementation of comprehensive greenhouse-gas-reduction program that includes increased renewable energy and cleaner fuel requirements, and mandatory emission reporting and fee requirements for major polluters such as power plants and oil refineries, until suspension is lifted."

Given deep pockets on both sides and the high cost of television advertising, spending on the initiative could reach $150 million, making it one of the most expensive ballot battles in the state's history.

The ballot will also be crowded with other controversial propositions, including an $11-billion state water bond, a measure to legalize and tax marijuana, an initiative to transfer authority over the redistricting of congressional districts from the Legislature to a commission and a measure to fund state parks with an $18 vehicle license fee.